1. Technical Field
The present invention relates to a printed circuit board having an isolation area for reducing signal interference between two layers.
2. Description of Related Art
A typical printed circuit board (hereinafter referred to as PCB) 10 includes a signal layer 11, a voltage source layer 12, and a ground layer 13, as shown in FIG. 3. The signal layer 11 is used as a layout for signal lines. A connecting area 112 is provided on the signal layer 11. A switch element 111 is positioned in the connecting area 112. The voltage source layer 12 is divided into a plurality of voltage areas 121, 122, 123 according to different voltage values. The connecting area 112 is positioned entirely in the voltage area 122.
The switch element 111 turns on and off periodically when receiving pulse signals, enabling current flowing through the connecting area 112 to be a pulsing current. However, the voltage in the area 122 of the voltage source layer 12 becomes unstable because of an interference caused by the pulsing current flow in the connecting area 112.
Therefore, a PCB having an isolation area for reducing signal interference is desired to overcome the above described deficiency.